Apparatus for transmitting radiant energy



F. A. KOLSTER.

APPARATUS FOR TRANSMITTING RADIANT ENERGY.

APPLICATION FILED NOV. 27. 916.

1,394,560, Patented Oct. 25, 1921.

2 SHEETS-SHEET I.

' lumcmio'a F. A. KOLSTER.

APPARATUS We TRANSMITTING RADIANI ENERL' \IiLHlHOi E|LD NOV 27 lHr.

1,394,560, Patented {but 25, 1921.

A FIG. 5.

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UNITED STATES FREDERICK A. ZKOLSTER, OF WASHINGTON, DISTRICT OF COLUMBIA.

APPARATUS FOR TRANSMITTING RADIANT ENERGY.

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Specification of Letters Patent.

Patented Oct. 25, 1921.

Application filed November 27, 1916. Serial No. 133,520.

T all wlwm it may concern:

Be it known that I, FREDERICK A. Kons- TER, a citizen of the United States, residing at Washington, D. (1., have invented a new and useful Apparatus for Transmitting Radiant Energy, of which the following is a specification.

My invention relates to radio signaling or control. systems involving the propagation through the natural media of electroradiant energy or electro-magnetic waves for telegraphy, telephony or any other signaling or control purposes.

My invention resides in apparatus for producing and impressing upon the natural media energy vibrating or alternating at high frequency either in the form of sus tained waves or waves in groups or wave trains, by recourse to structures and arrange ments in which the disadvantageous ell'ects of the distributed inductance and distributed capacity, or either, of a transmitting antenna, as now commonly employed and cont prising usually the open transmitting circuit, are overcome by employment as a radiating circuit one which is closed through inductance and capacity, which is all substantially lumped or concentrated and in which the distributed capacity and distributed inductance are each substantially oil and which, as a radiating circuit or path of oscillations for radiation purposes, lacks the usual high resistance of an antenna as commonly employed, and is therefore, in the sense employed in the radio art, a circuit of low resistance.

Such a circuit preferably takes the form of a coil or winding of oneor more turns or convolutions, which may be of any suit able shape. Such a coil is connected through conductors of practically no distributed in ductance or capacity with a capacity or condenser which forms a lumped or concentrated capacity as distinguished from the distributed capacity of an ordinary antenna. In such a circuit the oscillations may be set up in any well known manner or they may be produced in aprimary circuit and impressed by magnetic or copacitatrve coupling, or both, upon such closed circuit.

Furthermore, the physical dimensions of the apparatus are very small as compared with the antenna now commonly employed and the apparatus is relatively inexpensive and will find its application not only for high power long distance transmission, but also for portable transmitting apparatus, ship and lighthouse stations, moving vehicles such as automobiles, railroad trains and air craft, and particularly aeroplanes.

My invention resides further in apparatus for transmitting high frequency energy of the character referred to and reception thereof at a distant station by recourse to transmitting apparatus of the character above. described and receiving apparatus such, for example, as described in my prior Patent No. 1,311,654, July 29, 1919.

In such a system, even Where the oscillalions occur in groups or trains, as distinguished from sustained oscillation, they have so small a decrement that in effect they very closely approximate the conditions of sustained oscillations, with the result that at the receiving apparatus of like character the selectivity, tuning or resonance is higher sharper and better than in any system of which I am aware,

And in transmitting apparatus of the character herein described in which sustained oscillations are produced, by recourse to any suitable means, such as an electric arc, there results the advantage over the ordinary antenna that large amounts of energy may be transmitted without reinforcement of a certain harmonic or certain harmonics of the fundamental wave frquency, with the result that the oscillatory energy generated is practically completely transmitted at a given and fundamental frequency. This is of decided advantage over the ordinary antenna transmitting system in that where sustained oscillations are employed, and particularly as produced by an electric are. due to the distributed inductance and capacity of such antenna, a certain harmonic or certain harmonics of the fundamental frequency are reinforced, with the result that the effect and efliciency of the transmitting apparatus as a whole are diminished.

My invention resides further in apparatus for producing directive effects in transmission of electro-radiant energy.

For an uiulerstanding of my invention and a description of some of the forms my apparatus may take, reference is to be had to the accompanying drawings, in which:

Figure 1 is a diagrammatic representation of transmitting apparatus comprising a closed good radiating circuit inductively coupled with a closed persistently oscillating circuit.

Fig. 2 is a diagrammatic view of inductively coulped closed circuits of the general character refered to in connection with Fig. 1, but in which the capacity is of modified form for increasing or assisting radiation.

Fig. 3 is an arrangement similar to that in Fig. 2 in which, however, an arc is em ployed directly in the closed oscillating and radiating circuit for producing sustained oscillations therein.

Fig. 4 is an elementary perspective view illustrating a form my invention may take in which the inductance comprises two coils or windings whose planes are at an angle with respect to each other.

' Fig 5 is a diagrammatic view of transmitting and receiving apparatus employing the sameinductance, which comprises two,

coils disposed at an angle with respect to each other.

Fig. 6 shows an elemental transmitting circuit in which a spark gap is connected directly in series with said circuit.

Fig. 7 shows a 2-coil closed transmitting circuit in which an arc is connected directly 'in series in said circuit.

Fig. 8 shows a modification suitable for directive effects.

Referring to Fig. 1, A is a coil or winding of rectangular or any other suitable shape. It preferably consists of a plurality of convolutions or turns of wire or conductor. The arrangement may be-such that the axial length of the coil A is very short as compared with; its diameter, thou h my invention is not'limited' thereto. he conductor may be of any suitable material, and is preferably litzendraht or high frequency cable,

though it may be solid copper or other wire,

' or copper or other tube. The coil A is connected in a. closed circuit 'in series with the capacity or condenser C,,which may be adjustable, and the adjustable secondary s 'of an oscillation transformer whose adjustable primary is connected in closed circuit with an adjustable condenser or capacity C, "and a spark gap 9, which may be of the single gap type, as illustrated, or may be of any other suitable type. To the terminals of the gap g are connectd"'the terminals of the igh tension secondary S of a transformer T whose primary P is connected in circuit with a suitable source of'current G, such as a source of alternatng current, and a key or other signaling or controlling instrument is.

When the key is is closed the transformer T is energized and its secondary S charges the condenser C, to a high potential which breaks down the gap 9 with resultant hi h frequency oscillations in the circuit-g, p, whose frequency is dependent upon the capacity of the condenser C and the inductions, with the result that the coil A radiates into space energy of like frequency. In such an arrangement substantially all of the radiation takes place from the coil A, which is in effect the radiating element of the system. The radating element A is also-a directive radiator in that the intensit is greatest in the plane of t e coil, and is less in other directions.

Or the closed primary and secondary circuits may be detuned with respect to each other, especially when other types of spark gap are used, as for example, a quench gap, all inwell known manner. i

In any event, the radiating circuit including the coil A is of low resistance, especially in the sense employed in the ,radio art regarding antennae of the open type. Its inductance is substantially completely lumped or concentrated, that is, its distributed inductance is practically nil. The same is true as to its capacity as produced by the condenser C. Accordingly the structure is such that the ideal of an oscillation circuit is very closely approximated. Even when the oscillationsare in groups or-trains, as they are of radiation I when emplgiying a spark gap as described,

the amplitu es of successive waves in a train or group differ but slightly from each other, i

transmitted radio te egraphic signals over eighteen. and a half miles of wooded country to a receiving apparatus of the character described in connection with Fig. 5 herein, that is, employing two coils whose planes are at an angle with each other, the j coil.

A at the transmitting station being of 'four convolutions and twelve feet square,.w hile each of the coils A and B at the receiving end was only four feet square. i

In Fig. 2 the arrangement is substantially the sameas that described in connection with Fig. 1, except that the .condenser C is composed of the two capacity areas K and K neither of which, however, need be elevated or requires much room or space. These capacity areas are shown as plates, but may be of any other suitable structure, and one of them, as K,, may be connected to earth Ea by closir j the switch sw, though it will be understood that of all the closed radiating circuits herein described they may be completely isolated from earth.

In this arrangement which also is capable of directing radiation the capacity of the closed radiating circuit is procured by a structure which assists in radiation in that the larger separated capacity areas assist in radiating or augmenting 'the electrostatic component of the electro-radiantenergy, while the coil A is largely concerned only with the magnetic component.

Due to their relatively great size, as compared with an ordinary condenser like C of Fig. 1, the areas K and K, will, generally be fixed and therefore their capacity is substantially constant. To procure variable capacity in the closed radiating circuit including the coil A there may be connected in parallel to the condenser formed by the areas K and K, a variable condenser G which may be brought into circuit by closing the switch f. Then by varying the condenser C the total capacity of the radiating circuit may be varied for well known purposes, such as tuning or adjustment of wave length.

In Fi 3, a structure is shown similar to that of I ig. 2 in that the capacity areas K and K are employed, as well as a condenser C, if desired. Here again the capacity area K may be connected to earth Ea through switch sw. But the purpose of this figure is to illustrate the use in series in such a closed radiating circuit of an electric are D such as employed in now well known are transmitting sets, the energy being supplied to the are D in well known manner from a circuit whose conductors are indicated'at h and In series in the closed radiating circuit is' shown a small additional lumped inductance e in shunt to which is connected the key or other signaling device is. In operation, as is well understood in the art, the arc D will set up sustained oscillations in the closed radiating circuit and their frequency will be determined by the capacity and inductance of that circuit. By pressing the key It" the amount of inductance of the circuit is changed and the frequency of the oscillations is correspondingly changed and at such changed value produces dot, dash or other code or signal characters.

By using with the are a closed radiating circuit as described, whose distributed inductance and capacity are each substantially m'l, reinforcement of a harmonic of the fundamental oscillation frequency will not occur, as in the case of an ordinary antenna which has perforce distributed inductance and capacity. I

In place of using a single coil A in the closed radiating circuit, a plurality of such coils may be employed with their planes disposed at angles with respectto each other.

In Fig. 4 is shown such an arrangement in which two coils are employed, A, B, disposed at an angle with respect to each other, and rotatable about their vertical axis a. With the graduated are or scale coiiperates the pointer b movable with the coils A and B. Vvhen the coils A and B are used in transmitting, as explained in connection with Fig. 5, directive effect is procured by rotating the coils A, B to such position that the pointer points toward the receiving station, as S toward which the energy will be radiated more powerfully than in other directions, as for example, toward the station 5,. And when the coils A, B are used for receiving, as explained in connection with Fig. 5 and in my said prior application Serial Number 87,914, directive reception effects are procured by rotating the coils A, B to such position that the pointer 5 points toward the station, as from which a message is to be received.

One mouc of use of such coils is shown in Fig. 5, where they are connected in series with each other and to the terminals j and mof a double throw switch n, which in the position indicated connects the terminals j, m to the terminals 0 and g, respectively, and so includes in series with the coils A, I the adjustable condenser C and the adjustable secondary s of an oscillation transformer whose primary 7 is connected in series with the adjustable condenser C, and the are D to which current is supplied by the conductors h and i. In shunt to part of the secondary 6; is connected the key Ic for changing the wave length, as described in connection with Fig. 3.

When it is desired to receive a message the switch a is thrown over into its other position, whereby it connects the terminals j and m with the terminals 1' and t of a closed circuit including the adjustable receiving condenser C and the primary 1), of an oscillation transformer whose secondary s, is bridged by the adjustable condenser C, in circuit with which are connected the adjustable condenser C as a stop condenser, and any suitable wave detecting device, as for example, an audion,E comprising the plate electrode u, grid v, and incandescent filament w energized from the battery m. In circuit with the high tension battery y is connected the telephone receiver 2.

By using at both stations transmitting and receiving apparatus such as shown in Fig. 5, we have a system in which at the transmitter there is a closed good radiating circuit whose dimensions are small and whose distributed inductance and capacity are substantially n-il, and at the receiving station a closed good absorbing circuit, also of small dimensions, and whose distributed capacity and inductance are substantially m'Z, there being two closed circuits, primary and secondary, at the transmitting station,

and two closed circuits, primary and secondary, at the receiving station, though it will be understood that any appar atus of the character herein described may be employed to transmit to apparatus of anv suitable type at the receiving station.

\Vhere two closed circuits are employed at each station, as described, there is produced a very effective system whose selectivity is extremely high, due to the fact that the transmitted waves have extremely small damping, even if transmitted in groups or trains, and are received in an absorption system which is highly selective because of its low resistance and the lack of distributed capacity and inductance in the absorbing circuit.

And obviously there is the additional advantage in such a system, as described in my Patent No. 1311654, of the prevention of interference and static disturbances, and direction finding.

In Fig. 6 is shown a spark gap 9 directly in series in the closed radiating circuit including also the coil A and the condenser C, and in such respect is analogous to Fig. 3, where the are D is inserted directly in series in the closed radiating circuit.

In Fig, 7 there is shown an are D directly in series in the radiating circuit comprising in this instance the two coils A and B disosed at an angle with respect to each other.-

bviously in place of the are D there may be used a spark gap 9, as in Fig. 6.

Directive effect in transmission, that is, radiation of greater intensity in one direction than in other directions, is producednals or energy are to be radiated. In circuit with the condenser C is shown the coil .A which also may be long and low, its length extending in the direction in which the signals are to be sent or radiated. While in Fig.8 Ihave shown both the condenser and the coil long and low, it is to be underi stood that either of them may be long and lowand the other take any suitable form.

It will be understood as to all the forms of radiating and absorbing circuits herein described that they are of low resistance, in the high frequency sense, and their dis tributed capacity and distributed inductance are each substantially nil, thus apapproaching very closely the ideal for oscillatory circuits, and in consequence may be of relatively small physical dimensions, correspondingly inexpensive to manufacture, and in fact gaining certain advantages lost 1n the ordinary open antenna systems due to the distributed ca acity. distributed inductance and relative y high re-,

sistance thereof.

And as hereinbefore intimated the closed radiating circuit may be entirely isolated from earth or may be connected to earth, as by connecting one plate or armature of the condenser or capacity thereof to earth Ea, through switch sin, or by makingearth connection to any other suitable point or points in the circuit.

Obviously a plurality of windings A and B may be used in any of the relations where winding A only is shown; and vice versa, where windings A and B are shown, they may be supplanted by winding A only.

For purposes of radio telephony a telephone transmitter or telephone transmitting apparatus may be associated with the trans mitting apparatus herein described in any of the manners well understood in connection with radio telephony as heretofore practised with ordinary antenna radiators.

What I claim is:

1. A radiator comprising a closed radiating circuit, an inductance in said circuit, and

a capacity in-said circuit comprising large electric are connected in series in said circuit,

the distributed capacity and inductance of said circuit being substantially m'l.

, 3. Transmitting apparatus comprising a closed radiating circuit, lumped inductance in said circuit, a capacity in said circuit comprising large separated capacity areas, said capacity areas'and said inductance serving as radiating elements, and a condenser connected in parallel with the condenser formed by said capacity areas.

4. Radio apparatus comprising an inductance coil having a plurality of turns, a capacity area external to and separate from said coil, and a connection from said coil to said capacity area, said coil and said ca.- pacity area each co-acting directly with a natural medium for exchange of high frequenc energy therebetween.

5. adio apparatus comprising a rotatable inductance coil having a plurality of turns, a capacity area external to and separate from said coil, and a connection from said coil to said capacity area, said coil and said capacity area each co-acting directly with a natural medium for exchange of igh fre quency energy therebetween.

6. Radio apparatus comprising an axially short inductance coil consisting of a plu- ":ality of turns, a capacity area external to and separate from said coil, a condenser in circuit with said coil, and a connection from said coil 'to said capacity area, said coil. and said capacity area each co-acting directly with a natural medium for exchange of high frequency energy therebetween.

7. Radio apparatus comprising a rotatable axially short inductance coil consisting of a plurality of turns,-a capacity area external to and separate from said coil, :1 variable condenser in circuit with said coil, and a connection from said coil to said capacity area, Said coil and said capacity area each coacting directly with a natural medium for exchange of high frequency energy therebetween.

8. Apparatus for impressing electro-radiant energy upon the natural media, comprising a closed radiating circuit including capacity and a radiating inductance, said ca pacity comprising a radiating capacity area.

9. Apparatus for impressing electro-radiant energy upon the natural media, com prising a closed radiating circuit including capacity and a radiating inductance, said capacity comprising a radiating capacity area alined with said radiat ng inductance.

10. Apparatus for impressing electro-radiant energy upon the natural media, comprising a closed radiating circuit including capacity and a radiating inductance, said capacity comprising a radiating capacity area, the distributed capacity and inductance of said radiating circuit being very small.

11. Apparatus for impressing electro-radiant energy upon the natural media, comprising a closed radiating circuit including capacity and a radiating inductance, said capacity comprising a radiating capacitv area,

and a source 01"" oscillations in said radiating circuit.

12. Apparatus tor impressing electro-radt ant energy upon the natural media, compris ing a closed radiating circuit including capacity and a radiating inductance, said capacity comprising a radiating capacity area, and a source of sustained oscillations in said radiating circuit.

13. Transmitting apparatus comprising a closed radiating circuit, a source of oscillations in said circuit, a capacity and a radiating inductance coil in said circuit, said capacity comprising a. radiating capacity area, the distributed capacity and inductance of said radiating circuit being very small,

14. Transmitting apparatus c'oniprisino closed radiating circuit, an arc in said. circuit, a capacity and a radiating incur: nice coil in said circuit, said capacity compr u a radiating capacity area, the distrihutcd capa ity and inductance of said radiating cuit being "cry small.

15. Transmitting apparatus comprising a closed radiating circuit, a. plurality of capacities in said circuit, a radiating inductance coil in. said circuit, one of said capacities comprising a radiating capacity area.

16. Transmitting apparatus comprising a closed radiating circuit, a plurality of capacities in parallel .with each other in said circuit, a radiating inductance coil in said circuit, one of said capacities c mprising a radiating capacity area.

17. Transmitting apparatus comprising a closed radiating circuit, a plurality of capacities in said circuit, one of said capacities being variable, another of said capacities comprising a radiating capacity area, and a radiating inductance coil in said circuit.

Transmitting apparatus comprising a closed radiating circuit. a radiating inductance coil in said circuit, a capacity in said circuit comprising a radiating capacity area, and an earth connection to said capacity.

19. Transmitting apparatus comprising a closed radiating circuit, a radiating inductance coil in said circuit, a capacity in said circuit comprising a radiating capacity area, and a connection to earth from an armature of said capacity.

20. Apparatus for impressing clectro-radiant energy upon the natural media, comprising a closed radiating circuit including a capacity and a radiating inductance, said capacity comprising a radiating capacity area, and means for varying the inductance. of said circuit.

21.. Apparatus for impressing electroradiant energy upon the natural media, com prising a closed radiating circuit including capacity and a radiating inductance, said capacity comprising a radiating capacity area, and means for varying the capacity of said circuit.

22. Apparatus for impressing electroradiant energy upon the natural media, comprising a closed radiating circuit including capacity and a radiating inductance, said moaci compr sing a radiating capacity a area, and for varying the capacity and inductance of saidcircuit.

2-3. Transmitting apparatus comprising a closed radiating circuit, a radiating inductance coil in said circuit disposed with its plane substantially vertical, and acapacity in said circuit, said capacity comprising a. radiating capacity area.

24. Transmitting apparatus comprising a closed radiating circuit. radiating inductance coil in saidcircuit disposed with its plane substantially vertical, and a capacity in said circuit, said capacity comprising a substantially horizontal radiating capacity area.

Transmitting apparatus comprising a closed radiating circuit, a. plurality of radiating inductance coils in said circuit, and

prisin a radiating capacity area.

26. ransmitting apparatus comprising a closed radiating circuit, a plurality of radiating inductance coils in said circuit, and capacity in said circuit, said capacity comprising a radiating capacity area, said coils having their planes disposed at an angle with respect to each other.

27. Transmitting apparatus comprising a. closed radiating circuit, an axially short radiating inductance coil in said circuit having a plurality of turns and of dimensions small compared with the length of the radiated wave, and capacity in said circuit, said capacity comprising a radiatingv capacity area. i V

28. Transmitting apparatus comprising a closed radiiating circuit, an axially short radiating inductance coil in said circuit having a plurality of turns disposed in a vertical plane and of dimensions small compared with the length of the radiated wave, and

capacity in said circuit, said capacity comprising a radiating capacit area.

In testimony whereof affixed my signature this 24th day of November, 1916.

FREDERICK A. KOLSTER.

have hereunto 

